This invention relates to a cap assembly for the reservoir of a vehicular brake which comprises two parts such as a cap body and a cap cover and a method for producing the reservoir cap assembly.
A synthetic resin cap assembly for the reservoir of a vehicular brake which comprises two parts such as a cap body and a cap cover has been known. In the prior art reservoir cap assembly comprising the two parts, the cap body and cap cover are separately formed so as to have mating portions which contact face-to-face when the two parts are assembled, then assembled so as to cause the mating portions to contact face-to-face and finally are connected together by means of adhesive, heat welding or ultrasonic welding. However, in the prior art reservoir cap assembly referred to hereinabove, the adhesive applied to the contacting faces is easily attacked by the brake liquid within the reservoir when the parts are connected together by the adhesive. And when the two parts are connected together by means of heat welding or ultrasonic welding, it can not be expected that the contacting faces of the mating portions of the two parts are connected uniformly and perfectly and as a result, the contacting faces of the mating portions of the parts tend to easily separate from each other.
A cap assembly for the reservoir of a brake which is provided with a critical liquid surface warning device has been also known. In such a prior art reservoir cap assembly, when the reservoir in conjunction with which the reservoir cap assembly is employed is subjected to oscillation, the liquid or brake oil within the reservoir tends to flow from the interior of the reservoir through the vent hole in the cap into the chamber defined by the cap and thus, it is not possible to perfectly prevent the liquid from adhering to the sealant which seals the opening of the section containing the detection switch of the critical liquid surface warning device. As a result, such a prior art reservoir cap assembly having a critical liquid surface warning device has the disadvantage that the brake liquid tends to deteriorate the sealant formed of epoxy resin and the coating on the lead lines of the critical liquid surface warning device, damage the contact of the detection switch and cause short-circuit due to the contact between the lead lines.